This paper analyses a uniquely detailed data set of social integration characteristics of immigrants belonging to four non-native ethnic groups (i.e., Turks, Moroccans, Surinamese, and Antilleans) living in Dutch neighborhoods. It is well known that an individual's level of social integration is related to the ethnic composition and economic development of an immigrant's residential locality, as well as the generation of the immigrant. Yet, what is not known is whether the social and economic characteristics of adjacent or neighboring localities also influence an individual's level of social integration. Using a multilevel hierarchical analysis with spatial interaction effects, we examine the extent to which four social integration aspects of the bridging social capital of these immigrant groups are related to their ethnicity, their generation, their immediate locality, and the effects of the neighboring localities. Our findings regarding the effects of the ethnic concentration and economic development of the immediate locality along with the immigrant's generation broadly concur with existing studies. At the same time, however, we also find that the features of neighboring localities exert an additional influence on an individual's social integration over and above those related to the immigrant's generation and immediate locality. These additional spatial spillover effects are broadly in line with those associated with the immediate locality, but they are also sensitive to particular proxies for social integration which are employed. These spatial spillover effects on social capital and social integration have not been observed before.